The age, geological character and structural setting of quartz-pyrite veins in the Assynt Terrane, Lewisian Complex, NW Scotland.

A set of previously unrecognised quartz-pyrite veins are present in the Assynt Terrane of the mainland Lewisian Complex, NW Scotland. The veins cross-cut the Badcallian and Inverian fabrics, and the Scourie Dykes. The veins have been reworked by Laxfordian deformation fabrics (ca. 1.8 Ga) and later brittle faults of various ages. Fieldwork analyses suggest that the veins are a multi-modal system of tensile/hybrid fractures which are locally influenced by the existing foliation of the gneisses. They are inferred to have formed during regional NW-SE extension, an orientation that is almost orthogonal to the NE-SW extension direction associated with the intrusion of the Scourie Dykes. Microstructures within the quartz veins suggest that overprinting Laxfordian events reached maximum temperatures of 500°C under moderate strain rates, while pervasive ductile deformation was restricted mainly to the Canisp Shear Zone and was succeeded by brittle deformation as the temperature decreased but strain rates remained high within the shear zone. Re-Os dating of the pyrite within the quartz veins gives an age of 2259±61 Ma, placing the emplacement of the veins after the oldest dates for the Scourie Dykes (2420, 2400 & 2375 Ma) but before the youngest ages (1990 Ma). Sulphur isotope analysis suggests that the pyrite is of primitive mantle origin and may have been either stripped from the crust by fluid circulation or was associated with the intrusion of the Scourie dykes. The presence of the quartz-pyrite veins in both the Assynt and Gruinard Terranes suggest they were amalgamated during or prior to Inverian deformation while the absence of the veins in the Rhiconich Terrane is consistent with the suggestion that this terrane was not amalgamated until the Laxfordian Orogeny. The emplacement of the veins may linked to the formation and/or amalgamation of the Loch Maree Group supracrustal sequence

Geometrical analysis of the inland topography to assess the likely response of wave-dominated coastline to sea level: application to Great Britain

The need for quantitative assessments at a large spatial scale (103 km) and over time horizons of the order 101 to 102 years have been reinforced by the 2019 Special Report on the Ocean and Cryosphere in a Changing Climate, which concluded that adaptation to a sea-level rise will be needed no matter what emission scenario is followed. Here, we used a simple geometrical analysis of the backshore topography to assess the likely response of any wave-dominated coastline to a sea-level rise, and we applied it along the entire Great Britain (GB) coastline, which is ca. 17,820 km long. We illustrated how the backshore geometry can be linked to the shoreline response (rate of change and net response: erosion or accretion) to a sea-level rise by using a generalized shoreline Exner equation, which includes the effect of the backshore slope and differences in sediment fractions within the nearshore. To apply this to the whole of GB, we developed an automated delineation approach to extract the main geometrical attributes. Our analysis suggests that 71% of the coast of GB is best described as gentle coast, including estuarine coastline or open coasts where back-barrier beaches can form. The remaining 39% is best described as cliff-type coastlines, for which the majority (57%) of the backshore slope values are negative, suggesting that a non-equilibrium trajectory will most likely be followed as a response to a rise in sea level. For the remaining 43% of the cliffed coast, we have provided regional statistics showing where the potential sinks and sources of sediment are likely to be

Developing the principles of chair based exercise for older people: a modified Delphi study

Background Chair based exercise (CBE) is suggested to engage older people with compromised health and mobility in an accessible form of exercise. A systematic review looking at the benefits of CBE for older people identified a lack of clarity regarding a definition, delivery, purpose and benefits. This study aimed to utilise expert consensus to define CBE for older people and develop a core set of principles to guide practice and future research. Methods The framework for consensus was constructed through a team workshop identifying 42 statements within 7 domains. A four round electronic Delphi study with multi-disciplinary health care experts was undertaken. Statements were rated using a 5 point Likert scale of agreement and free text responses. A threshold of 70% agreement was used to determine consensus. Free text responses were analysed thematically. Between rounds a number of strategies (e.g., amended wording of statements, generation and removal of statements) were used to move towards consensus. Results 16 experts agreed on 46 statements over four rounds of consultation (Round 1: 22 accepted, 3 removed, 5 new and 17 modified; Round 2: 16 accepted, 0 removed, 4 new and 6 modified; Round 3: 4 accepted, 2 removed, 0 new and 4 modified; Round 4: 4 accepted, 0 removed, 0 new, 0 modified). Statements were accepted in all seven domains: the definition of CBE (5), intended users (3), potential benefits (8), structure (12), format (8), risk management (7) and evaluation (3). The agreed definition of CBE had five components: 1. CBE is primarily a seated exercise programme; 2. The purpose of using a chair is to promote stability in both sitting and standing; 3. CBE should be considered as part of a continuum of exercise for frail older people where progression is encouraged; 4. CBE should be used flexibly to respond to the changing needs of frail older people; and 5. Where possible CBE should be used as a starting point to progress to standing programmes. Conclusions Consensus has been reached on a definition and a set of principles governing CBE for older people; this provides clarity for implementation and future research about CBE

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

The Himalayan Question

The collision of India into Asia has produced the highest mountain belt on the planet, the Himalayas, which is often held to be the classic example of mountain building. Despite this, much about the mountain belt is not understood, including the unexpectedly vital role it plays in shaping our climate. Rowan Vernon explains more

Tectonic Evolution and Plateau Uplift around the Changma Basin in the Qilian Mountains, NE Tibetan Plateau

The Qilian Mountains are one of the most actively uplifting regions of the Tibetan Plateau and may provide a type example for the early evolution of its older regions. The mountains form a 300 km wide, NW – SE trending fold-thrust belt which extends 1000 km along the northeast margin of the Plateau and over-thrust the Hexi Corridor to the northeast and the Qaidam Basin to the southwest. An early-mid Palaeozoic orogenic suture belt, composed of faulted terranes of Late Proterozoic to early-mid Palaeozoic meta-sedimentary and meta-volcanic strata, is exposed in the Qilian Mountains and has been previously suggested to be reactivated by Late Cenozoic deformation. NE-directed crustal shortening, associated with the far-field effects of the Indo-Asian collision, has been active in the Qilian Mountains since the early-mid Miocene. It is characterised by the uplift of high mountain ranges along crustal scale thrust faults which splay south-eastwards from the sinistral-slip, north-northeast trending Altyn Tagh Fault and are postulated to connect along a shallow-dipping decollement in the midlower crust. Initiation of uplift in the Qilian Mountains was associated with a considerable decrease in the slip rate along the eastern end of the Altyn Tagh Fault and coincides with a plateau-wide reorganisation of deformation. This project presents new field mapping and remote sensing analysis and integrates this with existing geophysical data to i) understand and constrain the tectonic evolution of the northeast corner of the Qilian Mountains and the northwest corner of the Hexi Corridor, ii) examine the structural and lithological control of the Palaeozoic accretionary crust over Late Cenozoic deformation within the mountain ranges, and iii) establish the spatial and temporal extent of different styles of deformation within the northeastern Qilian Mountains

Tectonic Evolution and Plateau Uplift around the Changma Basin in the Qilian Mountains, NE Tibetan Plateau

The Qilian Mountains are one of the most actively uplifting regions of the Tibetan Plateau and may provide a type example for the early evolution of its older regions. The mountains form a 300 km wide, NW – SE trending fold-thrust belt which extends 1000 km along the northeast margin of the Plateau and over-thrust the Hexi Corridor to the northeast and the Qaidam Basin to the southwest. An early-mid Palaeozoic orogenic suture belt, composed of faulted terranes of Late Proterozoic to early-mid Palaeozoic meta-sedimentary and meta-volcanic strata, is exposed in the Qilian Mountains and has been previously suggested to be reactivated by Late Cenozoic deformation. NE-directed crustal shortening, associated with the far-field effects of the Indo-Asian collision, has been active in the Qilian Mountains since the early-mid Miocene. It is characterised by the uplift of high mountain ranges along crustal scale thrust faults which splay south-eastwards from the sinistral-slip, north-northeast trending Altyn Tagh Fault and are postulated to connect along a shallow-dipping decollement in the midlower crust. Initiation of uplift in the Qilian Mountains was associated with a considerable decrease in the slip rate along the eastern end of the Altyn Tagh Fault and coincides with a plateau-wide reorganisation of deformation. This project presents new field mapping and remote sensing analysis and integrates this with existing geophysical data to i) understand and constrain the tectonic evolution of the northeast corner of the Qilian Mountains and the northwest corner of the Hexi Corridor, ii) examine the structural and lithological control of the Palaeozoic accretionary crust over Late Cenozoic deformation within the mountain ranges, and iii) establish the spatial and temporal extent of different styles of deformation within the northeastern Qilian Mountains

Beyond access and equity : women's place in Austalian open learning

This paper acknowledges that open learning (in many of its manifestations) has obvious benefits for people who cannot access a university campus. We would argue, however, that there is a clear need to continually identify and discuss some of the other 'various reasons' that have impeded access to higher education for specific individuals and groups in order to ensure that the rhetoric and the image of"openness" does not function as a substitute for"real" open access. Focusing on the participation of women in open learning, therefore, we shall discuss in this paper, some of those 'reasons' which have functioned (and still do so) as impediments to access